(WFLX) - It happens over and over: Children left in dangerously hot cars.

In the South Florida heat, the inside of a car can easily turn into an oven.

"Two hundred and nine degrees on a black dash board, so that's three degrees away from boiling water," said a Palm Beach County firefighter.

That was the surface temperature, but to demonstrate how hot the air temperature can get, we parked our Fox 29 News car for about 30 minutes in the parking lot. Inside, the thermometer, told a scary tale. "It's been inside the car for about 25 to 30 minutes, and it's just around 150 degrees."

That's a temperature at which the human body is already failing. "Once the body reaches a core temperature, the inside temperature of 106 degrees, anything above that is damaging - not only to the brain, but also to vital organs," said Chief Chuck Lupo with Palm Beach County Fire Rescue.

Across Palm Beach County, the number of calls coming in about children left in cars is noticeably increasing. "Just yesterday, [Tuesday], there were three or four calls in reference to a child left in vehicle," said Jason Frisbie, PBC Fire Rescue. "Oh, it's nerve wrecking. It's people being complacent, just too much on their minds, but their children should be first."

But there are ways to not forget a child inside a car. For example, put your purse, gym bag or anything else you will need to go somewhere in the back seat. So that when you get down, you remember to take your child with you.

We got some statistics about the number of calls here in Palm Beach County related to a child being left inside a car.

April: 43

May: 40

June: 37

The problem is persistent, and fire rescue officials are asking parents to please be alert and attentive.